The gastrointestinal tract is responsible on synthesize and releasing of many peptide hormones that regulate eating behavior including pancreatic protein (PP), glucagon-like peptide 1 (GLP-1), peptide YY (PYY) and Oxyntomodulin (OXM). OXM arises from a tissue-specific post-transitional processing of proglucagon in the intestine and the CNS. It contains 37 amino acids, including the complete glucagon sequence with a C-terminal basic octapeptide extension that was shown to contribute to the properties of OXM both in-vitro and in-vivo but was not alone sufficient for the effects of the peptide. In response to food ingestion, OXM is secreted by intestinal L cells into the bloodstream proportionally to the meal caloric content.
OXM enhances glucose clearance via stimulation of insulin secretion after both oral and intraperitoneal administration. It also regulates the control of food intake. Intracerebroventricular (ICV) and intranuclear injection of OXM into the paraventricular and arcuate nuclei (ARC) of the hypothalamus inhibits re-feeding in fasting rats. This inhibition has also been demonstrated in freely fed rats at the start of the dark phase. Moreover, peripheral administration of OXM dose-dependently inhibited both fast-induced and dark-phase food intake.
Unfavorable pharmacokinetics, such as a short serum half-life, can prevent the pharmaceutical development of many otherwise promising drug candidates. Serum half-life is an empirical characteristic of a molecule, and must be determined experimentally for each new potential drug. For example, with lower molecular weight protein drugs, physiological clearance mechanisms such as renal filtration can make the maintenance of therapeutic levels of a drug unfeasible because of cost or frequency of the required dosing regimen.
Proteins and especially short peptides are susceptible to denaturation or enzymatic degradation in the blood, liver or kidney. Accordingly, proteins typically have short circulatory half-lives of several hours. Because of their low stability, peptide drugs are usually delivered in a sustained frequency so as to maintain an effective plasma concentration of the active peptide. Moreover, since peptide drugs are usually administered by infusion, frequent injection of peptide drugs cause considerable discomfort to a subject. Thus, there is a need for technologies that will prolong the half-lives of therapeutic proteins and peptides while maintaining a high pharmacological efficacy thereof. Such desired peptide drugs should also meet the requirements of enhanced serum stability, high activity and a low probability of inducing an undesired immune response when injected into a subject.
The present invention relates to OXM derivative in which the half-life of the peptide is prolonged utilizing a reversible pegylation technology.